This project will compare the effectiveness of high-dose/long- duration ACTH therapy with that of low-dose/short-duration ACTH therapy in stopping the seizures and improving the EEGs of patients who have infantile spasms. A single-blind design will be used, and approximately 60 patients with infantile spasms will be studied prospectively in a structured protocol in which response to therapy will be determined in an objective manner by utilizing long-term comprehensive EEG and video monitoring techniques previously developed in this laboratory. The two therapeutic regimens will also be compared for incidence of consequential side effects and for relapse rates. In addition, the effects of high-dose/long-duration vs low-dose/short-duration ACTH therapy on long-term outcome will be determined.